We heard the same thing before we went last May. Even mentioned it to our bell man. It was really hot when we were there, too hot to go out on our free upgrade balcony. I hate to be hot when I sleep. Didn't want to come back to a hot hotel room. We never, ever in 9 days had a problem with our room temperature. It was in the 90's and muggy every day we were there. Seems like the bell man did go over to the thermostat but can't remember for sure now.
We loved the Swan. And our room was very comfortable despite what I had read on the boards.